A station waiting room, closed after being repeatedly used as a toilet, has now been reopened during the morning rush hour.
In December 2012, South West Trains staff locked up the room on the platform of Motspur Park station after it was used as a toilet “in the most extreme sense”.
Residents had questioned whether the lack of a toilet at the station meant passengers were being caught short, but it is understood the waiting room was a target of antisocial behaviour.
Coun Mary-Jean Jeanes, who represents West Barnes ward, said: “I’m sure we all agree it is not fair to expect South West Trains staff to clear up such mess.
“However, it is also unfair that the majority of passengers are deprived of the waiting room.
She added: “We have suggested that CCTV could be used to prevent the recurrence of such anti-social behaviour and asked for the station toilets to be open more often.”
It comes after fellow West Barnes councillor, Gilli Lewis Lavender, submitted a petition with over 300 signatures to Merton Council calling for the waiting room to be reopened.
Coun Lewis-Lavender said: “People using Motspur Park pay the same fares as everybody else and there is a good waiting room there. It’s not acceptable that they just locked the door and walked away.
“They have got CCTV there already and they should put a camera in the waiting room.”
A spokeswoman for the South West Trains-Network Rail Alliance said: "We are pleased to report that there have been no instances of anti-social behaviour since the waiting room was re-opened and it will continue to be open in line with the ticket office opening hours.
"We have no immediate plans to introduce CCTV in the waiting room, however we constantly keep our security arrangements under review and will continue to make any changes as necessary."